BMW E30 Coolant Flush and Bleed

[@moon-cb2pl]

This is the video everyone needs. All the other ones never talk about the thermostat housing bleeding but the forums do!

[@bigilworth]

That's why I created this video. I couldn't find a good E30 video that showed how to bleed the system from the thermostat housing. BavAuto has a good BMW coolant flush video, but I think they were working on an E46 model. Similar process, but having a video showing an E30 helps those who are attempting something for the first time.

[@RuperScooper]

Great video just ordered my funnel and about to jump in on this one some very useful tips here and nicely shot clear concise and no waffle good job thx 🙏

[@bigilworth]

Awesome! Glad it was a big help!

[@MM-sf8wq]

Great video. Thank you for the funnel info!

[@bigilworth]

You're welcome! Really helps with all my car coolant jobs

[@Sharpened_Spoon]

Excellent video. Very thorough!

[@bigilworth]

Thank you!

[@riyadhel]

Great Video! I'm having a similar issue right now with my 90 325is. Fluid is just pouring out of the bottom left hand drivers side where i THINK the petcock is need to check tomorrow. Cars overheating and when i filling with coolant once the car reaches temp it all just floods out of the bottom left hand side. Is that the petcock area? or is that where the overflow is?

[@bigilworth]

You're correct, the petcock is on the left side of the radiator. If your petcock isn't broken, you might have a cracked radiator or broken hose. There is a hose from the thermostat housing to the radiator that could be loose.

[@riyadhel]

@@bigilworth thanks! Gonna take a look at that now. Ordered a new coolant thermostat and petcock screw from FCP just Incase. Hopefully my rad isn’t cracked just been having a rough time seeing where the leak is coming from lol

[@KriegBoy]

Thanks bro, have a nice day.

[@bigilworth]

Thank you too

[@chrispbmw8732]

Where does the hose on the left go to? The hose without the sleeve on the reservoir.

[@bigilworth]

That hose doesn't connect to anything and routes to the bottom of the chassis. It's part of the expansion tank's overfill safety mechanism. If the expansion tank builds up too much pressure and/or fluid, it can escape via that hose.

[@chrispbmw8732]

@@bigilworth thank you sir!!!

[@bigilworth]

@@chrispbmw8732 No problem! Hope you keep learning about these cool E30s!

[@rodrigoandrescepedaperez7877]

Hello dear friend. By chance you have the procedure of bleeding the cooling system, when the expansion tank is attached to the radiator. Greetings from Chile, South America.

[@bigilworth]

Hi. It should be exactly the same. If you're using the "no spill" funnel, you attach the funnel to the radiator, then fill it until no more coolant is entering the car. Then turn the car on and make sure that the funnel continues to have coolant while air bubbles out of the engine. AND make sure to every so often release the thermostat housing screw to release air. Sometimes air gets trapped there with no way of getting out. What car are you working on?

[@rodrigoandrescepedaperez7877]

@@bigilworth Hi. I"m working in my 1990 320i. Now I have some problems with the cooling system. There is not the original, I installed one radiator of Z3 model, with the expansion tank attached to radiator. Thanks

[@rodrigoandrescepedaperez7877]

When I make the procedure what you describe ...... the coolant level in the funnel go up slowly when the engine is working !!!

[@bigilworth]

@@rodrigoandrescepedaperez7877 Sounds like you're doing everything correctly. The level of the coolant will rise because as the engine warms up the coolant fluid will expand. If there are no air pockets in the cooling system and the coolant level in the funnel never goes down, that means your coolant system is full. What problems are you having with the cooling system? Over heating?

[@rodrigoandrescepedaperez7877]

@@bigilworth Yes, that's the problem ..... overheating. I made some adjusting, change the thermostat housing, water pump, thermostat and review the radiator work. Thanks

[@1devz1]

Just purchased this funnel kit to make the bleeding process easier. But before I attempt to bleed the system, I was wandering do you plug the overspill pipe during this process? Otherwise, the coolant stored in the funnel will just leak out of the overspill pipe?

[@bigilworth]

No need to plug the overspill funnel during the process. You actually want to keep it 1/2 full at all times to allow air to escape and more coolant to flow into the system. If you plug it up then air can't escape nor can coolant enter the system. Once you feel that the system has been bleed of all air, turn the car off and then plug the overspill funnel. That way when you detach it from the coolant reservoir, no coolant will spill out all over the place. You'll most likely need to remove some coolant from the reservoir afterwards because it will be right at the top of the cap. I usually do that with a turkey baster. Good luck!

[@1devz1]

@@bigilworth sorry I should have been more clear. I was referring to the overflow pipe from the reservoir tank which drains out to the bottom of the chassis when there is noo much pressure/coolant in the system. Does this pipe need to be plugged when using the funnel method?

[@bigilworth]

@@1devz1 Ah gotcha. No that pipe doesn't vent extra coolant unless the system becomes over pressurized. It wasn't until I was doing a spark plug job and had to move the reservoir, (which was months after using this funnel and creating the video), that I even noticed that vent tube. Definitely no coolant came out of that tube while bleeding the system and while using that funnel. However if it makes you feel more comfortable, you could just plug it. A simple clamp or rubber plug will do the trick.

[@1devz1]

@@bigilworth thanks for taking the time to reply bud! 😁

[@bigilworth]

@@1devz1 Yea man, good luck. Always willing to help the E30 community.

[@javierhernandez215]

The hell with the e46 process i am doing this, I've done as per instruction and never got it right but a mess in the floor

[@bigilworth]

HAHA! The E30 manual process says to squish the top hose a bunch and keep the bleeder valve open for long stretches until the coolant starts flowing out - After my first time doing that I had coolant everywhere and said there HAS to be a better way. Hope it works out for you next time with the Coolant funnel

[@r.dimasmuhammadzukhrufiazh2948]

I have a 520is E28 M20 1988, am i doing like this too? Same process?

[@bigilworth]

Checking out the photos of the E28, it seems that all M20 engines have the same bleeder screw, thus the process should be the same.

[@r.dimasmuhammadzukhrufiazh2948]

@@bigilworthit's All good, I have a same engine... exactly. Thank you mate 😊

[@scottmason1012]

Question: Thanks again for replying to my earlier comment. I followed these steps but when I went to drain the water from my system (after letting it circulate through the engine) not all of the water came out (only about a gallon). How do I get the rest of the water out?? And my vents were not blowing any hot air during this process (so I guess I have air in my heater core). Any help is appreciated!

[@bigilworth]

If only a gallon came out of the system, then you did everything correct. There is about another 3/4 gallon in the block of the engine. If you want to get that out too, there is a screw on the engine block passengers side that will release more coolant. 0.26 of my video shows a photo of where it is located. I decided not to unscrew the engine block coolant plug because I was having difficulty getting the plug to unscrew and I didn't feel like soaking it with penetrating oil. I ended up driving 200 miles and then did another coolant flush. If your vents are not blowing cold air, you either have air trapped in the heater core or the pipe that regulates when coolant goes into the heater core is stuck shut. Did the hot air work before you tried bleeding the system? Here is a video that shows the heater core regulator. kzbin.info/www/bejne/qmKkmn6Amracmc0

[@scottmason1012]

@@bigilworth Thank you for your reply. That makes me less worried :) I actually just replaced the heater control valve (which is why I flushed the system) but it was a used part so I am hoping it works and I just have air in the system. Also yes, the vents did blow hot air during the winter

[@jayelectic8017]

What if the car doesnt start?

[@bigilworth]

If you can't start the car, there is no reliable way to bleed the air out of the coolant system because you can't get the water pump to work. I would work on getting the car to start before you do a coolant flush.

[@jayelectic8017]

@@bigilworth oh no! So i bought this car as a project build and i wasn’t really thinking of it i thought id take the rad out since it was rusty and replace it with the one i have from a donor car. Did i just mess something up? This is my very first project car the car wasnt running when i bought it it has a few missing parts thats why it came with a donor car.

[@bigilworth]

@@jayelectic8017 You didn't mess anything! It only means you can't bleed the air out of the coolant system until you get the car started. If you were to do an engine rebuild, you'd have the same problem - doing a coolant change before having the car start for the first time. You're totally fine. After you get the system filled with as much coolant as it will take, start working on getting the car to start and run. Once it's running, then follow the video's procedures for bleeding air out of the system. You'll want to have the funnel filled with coolant to allow bubbles to work themselves out. E30s are incredibly fun to work on because they're so easy to work on. You'll have a great time trying to get the car running.

[@scottmason4476]

when do you put the bleeder screw or "petcock" back in? After you have drained all the coolant and begin the process of refilling?

[@bigilworth]

Put the bleeder screw back in and tighten shut once all the fluid is drained. If you don't have the screw in before you start filling the system back up with fluid, everything will leak out as you start filling the system.

[@Theooo666]

Hi! I know it's a "basic" item but where did you find this funnel? And if I understand it is used to keep the level higher than anything to facilitate the evacuation of air bubbles, is that it?

[@bigilworth]

Thank you for the comment. Do an amazon search for "coolant overspill funnel" and you'll find all the different companies making these funnels. The brand I used in the video is Lisle. You are correct that the point of these funnels is to facilitate the bleeding of air inside the radiator system. It makes the air bleeding process incredibly easy and it reduces the messiness of bleeding air out of the system. Good luck!

[@scraw188]

@@bigilworth does the funnel have to be specific to e30?

[@bigilworth]

@@scraw188 Nope. Any brand of "no-spill" funnels will work. They all come with a bunch of different radiator attachments, so you can attach the funnel to any car.

[@davidt4156]

Is adding water to the coolant necessary because I don’t mind spending a few extra bucks rather then diluting it to get more out of it

[@bigilworth]

Pretty much all engines require a 50/50 mix of water and coolant. If you put 100% coolant into your engine you'll end up eroding the metals inside the engine and the seals, creating coolant leaks or head gasket failure. I think the highest recommended is 70/30 (coolant/water). The other reasons why you don't want to over due it is because your engine will not warm up to operating temperature fast enough, causing lean fuel mixture conditions. The best thing to do is flush out the engine's coolant every 2-3 years or every 40,000 miles. Fresh coolant helps the engine's metals from eroding and keeping the radiator clean of debris. Hope this helps!

[@Ben-Hawy]

If you have a aluminum heads you should not use the green antifreeze

[@bigilworth]

The forums are all over the place with modern coolant. Now the general philosophy is just use the same type, don't mix. Prestone is a general coolant for any vehicle and because my E30 is so old and crappy, I'm not concerned about super longterm damage to the block or head. After 5 years and 60k miles of running Prestone, I haven't had any issues. I agree though with you that if I was to use correct BMW coolant, I'd use the blue stuff.

[@OpenAirAdventureFirewood]

Perfect thankyou

[@bigilworth]

You're welcome!

[@fearthereaper5663]

M20b23?

[@bigilworth]

M20B27. The model is the E30 325e. But the procedures works for the M20B25 engines too. They have the same exact bleeder valve setup.

[@PhyteByte]

So.. the video is about your fancy funnel

[@bigilworth]

If you watch the video you'll see I describe the process of bleeding the air out of the system using the bleeder screw on the thermostat housing. But it is also about how the fancy funnel makes bleeding the system easy and with zero spillage.